Fluid typography scales type continuously across viewport sizes using CSS clamp() and modular scales, eliminating stepped breakpoints in favor of math-driven relationships between minimum, maximum, and preferred font sizes.

Responsive design is shifting away from viewport breakpoints toward intrinsic, component-aware CSS — fluid sizing, container queries, and platform primitives that let layouts and typography adapt without media-query thresholds.

Web accessibility spans technical decisions across CSS, typography, and HTML structure that determine whether interfaces remain usable for all people, regardless of device, ability, or preference.